Testosterone-mediated upregulation of delayed rectifier potassium channel in cardiomyocytes causes abbreviation of QT intervals in rats.

ABSTRACT: Men have shorter rate-corrected QT intervals (QTc) than women, especially at the period of adolescence or later. The aim of this study was to elucidate the long-term effects of testosterone on cardiac excitability parameters including electrocardiogram (ECG) and potassium channel current. Testosterone shortened QT intervals in ECG in castrated male rats, not immediately after, but on day 2 or later. Expression of Kv7.1 (KCNQ1) mRNA was significantly upregulated by testosterone in cardiomyocytes of male and female rats. Short-term application of testosterone was without effect on delayed rectifier potassium channel current (I_Ks), whereas I_Ks was significantly increased in cardiomyocytes treated with dihydrotestosterone for 24 h, which was mimicked by isoproterenol (24 

SUBMITTER: Masuda K 

PROVIDER: S-EPMC10717990 | biostudies-literature | 2018 Nov

REPOSITORIES: biostudies-literature